Clinical application of sensory protection of denervated muscle

Abstract

Following proximal peripheral nerve injury, motor recovery is often poor due to prolonged muscle denervation and loss of regenerative potential. The transfer of a sensory nerve to denervated muscle results in improved functional recovery in experimental models. The authors here report the first clinical case of sensory protection. Following a total hip arthroplasty, this patient experienced a complete sciatic nerve palsy with no recovery at 3 months postsurgery and profound denervation confirmed electrodiagnostically. He underwent simultaneous neurolysis of the sciatic nerve and saphenous nerve transfers to the tibialis anterior branch of the peroneal nerve and gastrocnemius branch from the tibial nerve. He noted an early proprioceptive response. Electromyography demonstrated initially selective amelioration of denervation potentials followed by improved motor recovery in sensory protected muscles only. The patient reported clinically significant functional improvements in activities of daily living. The authors hypothesize that the presence of a sensory nerve during muscle denervation can improve functional motor recovery.

Fig. 1

Drawing showing intraoperative exploration of the injured sciatic nerve. Once the piriformis muscle is reflected and the sciatic is identified, neurolysis is performed with the aid of an operating microscope. The procedure is continued until bands of Fontana are observed. Following neurolysis, deposteroid is injected locally.

Fig. 2

Schematic illustrating the step-by-step sensory protection procedure. Left: Anterior surgical exposure. Right: Anterior exposure to tibialis anterior muscle and deep branches of the peroneal nerve.

Fig. 3

Diagram demonstrating the step-by-step sensory protection procedure. Left: Posterior surgical exposure. Right: Posterior exposure to gastrocnemius muscles and their innervation.

Fig. 4

Drawing showing exposure and distal division of the saphenous nerve in preparation for transfer.

Fig. 5

Schematic revealing sensory protection of the right tibialis anterior (anterior view) and gastrocnemius (posterior view) muscles by end-to-side connection of fascicles of the right saphenous nerve.